How to enable MariaDB/MySQL logs ?




As a web developer that have been toying with MySQL/MariaDB for more than 5 years. I can tell you that the best way to start debugging your application or looking for ways to improve database performance is to enable the logs. To enable the MySQL/MariaDB logs :

Edit MySQL configuration file:

vi /etc/mysql/my.cnf

Note : Depending on your installation, the my.cnf file could be located on different directory. MariaDB's my.cnf is located at /etc/my.cnf

Slow Query Log

To enable Slow Query Log, add these lines or uncomment these two lines. Change the destination location for the log files if you prefer.

logslowqueries = /var/log/mysql/mysql-slow.log

longquerytime = 2

log-queries-not-using-indexes

To enable Error Log, add these lines or uncomment these two lines. Change the destination location for the log files if you prefer.

[mysqld_safe]

logerror=/var/log/mysql/mysqlerror.log

[mysqld]

logerror=/var/log/mysql/mysqlerror.log

To enable General Query Log, add these lines or uncomment these two lines. Change the destination location for the log files if you prefer.

generallogfile = /var/log/mysql/mysql.log general_log = 1

To enable these changes, restart mysql

sudo /etc/init.d/mysql restart

or

sudo service mysql restart

References :

http://dev.mysql.com/doc/refman/5.7/en/slow-query-log.html

http://dev.mysql.com/doc/refman/5.7/en/error-log.html

http://dev.mysql.com/doc/refman/5.7/en/query-log.html





By Adam Ng

IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.


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